Process for the treatment of polymer compositions

ABSTRACT

A process for the preparation of heterophasic elastomeric polymer comprising the step of polymerizing ethylene, an alpha-olefin CH2=CHL, where L is an alkyl, cycloalkyl or aryl radical with 1-10 carbon atoms and a non-conjugated diene in the presence of a catalyst system comprising a transition metal catalyst component supported on a porous alpha-olefin polymer, characterized in that at least part of the diene is impregnated on the porous alpha-olefin polymer.

The present invention relates to a process for the preparation of anelastomeric polymer composition comprising the steps of polymerizingethylene, an alpha-olefin and a non-conjugated diene in the presence ofa catalyst system based on a transition metal component supported on aporous polyolefin.

The most common polyolefin elastomers produced are copolymers ofethylene and propylene (EPM) and terpolymers of ethylene, propylene anda diene (EPDM). Ordinary EPDM elastomers can be cured using suchcuratives as organic peroxides, phenolic resins or sulphur. In mostcurrent EPDM production, the catalysts conventionally employed in theproduction of high molecular weight EPDM elastomers are soluble vanadiumcatalysts such as VC₄, VOCl₃, VO(Ac)₃, V(Acac)₃ or VO(OR)₃ where R is analkyl group together with an organoaluminum compound. The activity ofthe vanadium catalysts are relatively low, e.g., producing 5-20 kgpolymer/g vanadium.

Metallocene compounds have been used for the production of EPDM, forexample Kaminsky et al., J. Poly. Sc., Vol. 23, 2151-2164 (1985)discloses the use of a metallocene-methylaluminoxane (MAO) catalystsystem to produce low molecular weight EPDM elastomers. Such catalystsrequire long reaction times and provide low yields and are thereforeimpractical for commercial EPDM manufacture. Other polymerizationprocesses for producing EPDM featuring the use of a metallocene catalystactivated by an aluminoxane such as MAO are described in U.S. Pat. Nos.4,871,705, 5,001,205, 5,229,478 and 5,442,020, EP 347,129 and WO95/16716. In particular, EP 593 083 describes a gas phase polymerizationprocess for producing EPDM employing a bridged metallocene catalystintroduced in the reactor in the form of droplets.

EPDM terpolymers are often used as components for blends with otherpolymer having different characteristics, such as differentcrystallinity. In particular they are blended with isotacticpolypropylene for obtaining the so-called TPV polymer.

One method of making the above mentioned blends is by mixing twodifferent polymers after they have been polymerized to achieve a targetset of properties. Such a method is very expensive and time-consumingand making reactor blends is much more desirable.

Blends by direct polymerization are well known in the art EPDM can beblended by using soluble vanadium based catalysts by using reactors inseries and making a polymer with different properties in each reactor.

WO 99/45046 relates to a process for producing reactor blends in which,in the presence of a metallocene catalyst in one reactor EPDMterpolymers are produced and in a second reactor propylene ispolymerized in the presence of the polymer produced in the firstreactor.

A drawback of obtaining EPDM by using metallocene catalysts, is that thepresence of the diene lowers the activity of the catalyst. Moreover,often the non-conjugated diene has a poor randomisation in the polymericchain, especially in a gas phase process.

An object of the present invention is a process for the preparation ofan elastomeric polymer composition containing EPDM polymers, in highyields and with a random incorporation of the non-conjugated diene. Thiscan be achieved according to the invention by impregnating the dienemonomer onto a porous alpha-olefin polymer.

Thus, the present invention provides a process for the preparation ofelastomeric polymer compositions comprising a polymerization step inwhich ethylene, an alpha-olefin of formula CH₂═CHL, where L is an alyl,cycloalkyl or aryl radical with 1-20 carbon atoms and a non-conjugateddiene are polymerized in the presence of a catalyst system comprising atransition metal catalyst component supported on a porous alpha-olefinpolymer, characterized in that at least part of the diene is impregnatedon the porous alpha-olefin polymer. According to embodiments of theinvention at least 10%, or at least 20% or at least 50% of the totaldiene used, is impregnated on a porous alpha-olefin polymer.

For the purpose of the present invention the term impregnated means thatthe diene is retained in the porous alpha-olefin polymer.

According to an embodiment, the process of the present inventioncomprises the following steps:

-   -   a) impregnating a porous alpha-olefin polymer with, in any        order, a non conjugated diene and a catalyst system based on a        transition metal compound; and then    -   b) polymerizing ethylene, an alpha olefin of formula CH₂═CHL,        where L is an alkyl, cycloalkyl or aryl radical with 1-10 carbon        atoms, and optionally a non-conjugated diene in the presence of        the supported catalyst obtained in step a).

According to another embodiment, the impregnation step a) is performedby:

-   -   a1) first impregnating the porous alpha-olefin polymer with the        non-conjugated diene; and then    -   a2) impregnating the product obtained in step al) with the        catalyst based on a transition metal compound.

The polymerization process can be carried out in the liquid phase in thepresence or absence of an inert hydrocarbon solvent, or in the gasphase. When present, the hydrocarbon solvent can be either aromatic,such as toluene, or aliphatic, such as propane, hexane, heptane,isobutane or cyclohexane. When the polymerization step b) is carried outin the gas phase, it is suitably done in a fluidized bed reactor.

The polymerization temperature is generally comprised between −100° C.and +200° C., and, suitably, between 10° C. and +90° C. Thepolymerization pressure is generally comprised between 0.5 and 100 bar.

The porous alpha-olefin polymer is a polymer obtained by polymerizingethylene or olefins of formula CH₂═CHL, where L is an alkyl, cycloalkylor aryl radical with 1-20 carbon atoms. examples of alpha-olefinspolymers are: polyethylene, polypropylene, polybutene, copolymers ofpropylene and copolymers of ethylene. It is generically used in anamount comprised between 5% and 70% by weight of the total polymerproduced in the process, preferably between 10% and 50% by weight, morepreferably between 25% and 50% by weight. Said alpha-olefin polymer hasa pore volume greater than 0.45 cc/g (determined by mercury absorption);preferably, greater than 0.5 cc/g; more preferably greater than 0.55cc/g. In a suitable embodiment said porous alpha-olefin polymer is anhomopolymer or a copolymer of propylene or ethylene.

Two particularly suitable classes of porous propylene polymers are thoseobtained according to WO 0146272 and WO 02/22732 particularly goodresults are obtained when the catalyst described in WO 0146272 is usedwith the process described in WO 02/22732. Polymers obtained accordingto WO 0146272 have a high content of the so-called stereoblocks, i.e. ofpolymer fractions which, although predominantly isotactic, contain a notnegligible amount of non-isotactic sequences of propylene units. In theconventional fractionation techniques such as the TREF (TemperatureRising Elution Temperature) those fractions are eluted at temperatureslower than those necessary for the more isotactic fractions. Thepolymers obtained according to the process described in WO 02/22732 showimproved porosities.

A suitable propylene homopolymer used as support in step a) has thefollowing characteristics:

-   -   flexural modulus (THOD ASTM D-5023) lower than 1200 Mpa;        preferably lower than 1000 Mpa, more preferably lower than 900        Mpa.    -   in the Temperature Rising Elution Temperature analysis (TREF)        the fraction eluted at a temperature range from 25° C. to 97° is        higher then 20% preferably higher than 30%; more preferably        higher than 40% of the total polymer eluted;    -   a melting enthalpy lower than 90 J/g; preferably lower than 80        J/g; more preferably lower than 70 J/g;    -   a pore volume (determined by mercury absorption) greater than        0.45 cc/g; preferably greater than 0.5 cc/g; more preferably        greater than 0.55 cc/g.

The use of this class of polymers give rise a better impregnation of thediene and of the transition metal catalyst component that leads to anincreasing of the activity of the catalyst system in the presence of thediene and to a reducing of the fouling. Moreover, with this polymer thecompatibility between the polymeric matrix and the terpolymer isenhanced.

Preferably the elastomeric texpolymer prepared in step b) contains from20% to 90% by weight of ethylene derived units, more preferably from 30%to 85% by weight, even more preferably from 35% to 70% by weight.

In a suitable embodiment, the alpha-olefin component of formula CH₂═CHLis selected from the group consisting of C₁-C₂₀ alpha-olefins.Illustrative non-limiting examples of such alpha-olefins are propylene,1-butene, 1-pentene, 1-hexene, 1-octene and 1-dodecene. Preferredalpha-olefin is propylene. Elastomeric polymers generally contain from10% to 80% by weight, more preferably from 20% to 65% by weight, ofCH₂═CHL derived units, preferably of propylene derived units.

The non-conjugated diene component of the terpolymer, which isimpregnated on the porous alpha olefin polymer at least in part beforethe polymerization step, can be a straight chain, branched chain orcyclic hydrocarbon diene having from 6 to 20 carbon atoms. Examples ofsuitable non-conjugated dienes are:

-   -   straight chain acyclic dienes, such as 1,4hexadiene and        1,6-octadiene;    -   branched chain acyclic dienes, such as 5-methyl-1,4hexadiene,        3,7-dimethyl-1,6-octadiene, 3,7-dimethyl-1,7-octadiene and mixed        isomers of dihydro myricene and dihydroocinene;    -   single ring alicyclic dienes, such as 1,3-cyclopentadiene,        1,4-cyclohexadiene, 1,5-cyclooctadiene and 1,5-yclododecadiene;    -   multi-ring alicyclic fused and bridged ring dienes, such as        tetrahydroindene, methyl tetrahydroindene, dicyclopentadiene,        bicyclo-(2,2,1)-hepta-2,5-diene; and    -   alkenyl, alkylidene, cycloalkenyl and cycloakylidene norbomenes,        such as 5-methylene-2-norbomene (MNB), 5-propenyl-2-norbomene,        5-isopropylidene-2-norbomene,5-(4-cyclopentenyl)-2-norbomene,        5-cyclohexylidene-2-norbomene, 5-vinyl-2-norbomene and        norbomadiene.

Preferred dienes are 1,4hexadiene (HD), 5-ethylidene-2-norbomene (E?NB),5-vinylidene-2-norbomene (VNB), 5-methylene-2-norbomene (MNB) anddicyclopentadiene (DCPD). Particularly preferred dienes are5-ethylidene-2-norbornene (ENB) and 1,4-hexadiene (HD).

The non-conjugated dienes are generally incorporated into the terpolymerin an amount from 0.5% to about 20% by weight; preferably from 1% to 15%by weight, and more preferably from 2% to 10% by weight. If desired,more than one diene may be incorporated simultaneously, for example HDand ENB, with total diene incorporation within the limits specifiedabove.

The diene can be impregnated into the porous polymer with variousmethods. For example, the porous polymer can be put in contact with asolution of the diene in a solvent such as propane, under stirring. Thesolvent is then removed, for example, by flashing the solution.

Non limitative examples of the transition metal catalyst component arecompounds of titanium not containing metal-π bonds supported on a Mghalide, compounds of vanadium and metallocene compounds.

In an embodiment the catalyst system used in the process of the presentinvention comprises:

-   -   A) a compound of formula TiCl₄, TiCl₃ or Ti(OT¹)_(f)T² _(g-f),        T¹ being a hydrocarbon radical containing up to 15 carbon atoms        or a —COT³ group, T³ being a hydrocarbon radical containing up        to 15 carbon atoms, T² being a halogen, f ranges from 1 to 4 and        g is the valence of titanium, supported on Mg halide, preferably        on active MgCl₂;    -   B) an internal electron-donor;    -   C) an aluminium-alkyl compound (Al-alkyl); and optionally    -   D) one or more external electron-donors.

Non-limiting examples of aluminium-alkyl compounds are compound offormula H_(j)AIR¹⁷ _(3-j) or H_(j)Al₂R¹⁷ _(6-j), where R¹⁷ substituents,same or different, are hydrogen atoms, halogen atoms, C₁-C₂₀-alkyl,C₃-C₂₀-cyclalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl or C₇-C₂₀-aylalkyl,optionally containing silicon or germanium atoms with the proviso thatat least one R¹⁷ is different from halogen, and j ranges from 0 to 1,being also a non-integer number. Example of these compounds are Al(Me)₃,Al(Et)₃, AlH(Et)₂, Al(iBu)₃, AlH(iBu)₂, Al(iHex)₃, Al(iOct)₃,AlH(iOct)₂, Al(C₆H₅)₃, Al(CH₂—CH(Me)CH(Me)₂)₃, Al(CH₂C₆H₅)₃,Al(CH₂CMe₃)₃, Al(CH₂SiMe₃)₃, Al(Me)₂iBu, Al(Me)₂Et, AlMe(Et)₂,AlMe(iBu)₂, Al(Me)₂iBu, Al(Me)₂Cl, Al(Et)₂Cl, AlEtCl₂ and Al₂(Et)₃Cl₃,wherein Me=methyl, Et=ethyl, iBu=isobutyl, iHex=isohexyl,iOct=2,4,4-trimethyl-pentyl. The above mentioned Al-alkyl compounds canbe used either alone or in mixtures thereof Amongst the above aluminumcompounds, trimethylaluminium (TMA), triisobutylaluminium (TIBAL) andtris(2,4,4-trimethyl-pentyl)aluminium (TIOA) are preferred.

The internal electron-donor compounds can be selected from ethers,esters, arnines, ketones and the like. Non-limiting examples are alkylesters, cycloalkyls and aryls of polycarboxylic acids, such as phthalicand maleic esters and ethers, such as those which are described in EP-A45977, the disclosure of which is incorporated herein by reference. Theexternal donor can be the same or can be different from the internaldonor. A particularly preferred class of external donor comprises alkylor alkoxy silanes of formula R^(1a) _(c)R^(2a) _(d)Si(OR^(3a))_(e)wherein R^(1a), R^(2a) and R^(3a) equal to or different from each otherare C₁-C₂₀ alkyl radical, c and d range from 0 to 2 being c+d equal to 1or 2 and e is 2 or 3 being c+d+e=4. When using diether compounds asthose as disclosed in the European patent application EP-A-361494, thestereospecificity of the catalyst is sufficiently high, such that thepresence of an external-donor is not required.

Examples of these kind of catalysts are disclosed, for instance, in U.S.Pat. No. 4,399,054 and U.S. Pat. No. 5,221,651, the disclosure of whichis incorporated herein by reference.

In another embodiment, the catalyst system used in the process of thepresent invention comprises:

-   -   A) a compound of formula VCl₃, VCl₄, VOCl₃, VO(Ac)₃, V(Acac)₃ or        VO(Ot⁴)₃ where T⁴ is a C₁-C₁₀ alkyl group, Ac is an acetate        group and Acac is an acetoacetate group; and    -   B) an aluminium-alkyl compound (Al-alkyl).

Aluminium alkyl compound are the aluminium compound disclosed above.Preferred vanadium compound is V(Acac)₃ used in conjunction withAluminium aLkyl compound containing an halogen atom, preferablychlorine.

In a furher embodiment, the catalyst system used in the process of thepresent invention comprises:

-   -   (A) a metallocene compound belonging to the following formula        (I)        (Cp)(ZR¹ _(m))_(n)(A)_(r)MX_(p)   (I)        wherein (ZR¹ _(m))_(n) is a divalent group bridging Cp and A; Z        being C, Si, Ge, N or P, and the R¹ groups, equal to or        different from each other, being hydrogen or linear or branched,        saturated or unsaturated C₁-C₂₀ alkyl, C₃-C₂₀ cycloalkyl, C₆-C₂₀        aryl, C₇-C₂₀ alkylaryl or C₇-C₂₀ arylalkyl groups or two R¹ can        form a aliphatic or aromatic C₄-C₇ ring;    -    Cp is a substituted or unsubstituted cyclopentadienyl group,        optionally condensed to one or more substituted or        unsubstituted, saturated, unsaturated or aromatic rings,        containing from 4 to 6 carbon atoms, optionally containing one        or more heteroatoms;    -    A is O, S, NR², PR² wherein R² is hydrogen, a linear or        branched, saturated or unsaturated C₁-C₂₀ alkyl, C₃-C₂₀        cycloalkyl, C₆-C₂₀ aryl, C₇-C₂₀ alkylaryl or C₇-C₂₀ arylalkl, or        A has the same meaning of Cp;    -    M is a transition metal belonging to group 4, 5 or to the        lanthanide or actinide groups of the Periodic Table of the        Elements (IUPAC version);    -    the substituents X, equal to or different from each other, are        monoanionic sigma ligands selected from the group consisting of        hydrogen, halogen, R³, OR³, OCOR³, SR³, NR³ ₂ and PR³ ₂, wherein        R³ is a linear or branched, saturated or unsaturated C₁-C₂₀        alkyl, C₃-C₂₀ cycloalkyl, C₆-C₂₀ aryl, C₇-C₂₀ alkylaryl or        C₇-C₂₀ arylalkyl group, optionally containing one or more Si or        Ge atoms; preferably, the substituents X are the same;    -    m is 1 or 2, and more specifically it is 1 when Z is N or P,        and it is 2 when Z is C, Si or Ge;    -    n is an integer ranging from 0 to 4;    -    r is 0,1 or 2; preferably 0 or 1; n is 0 when r is 0 or 2;    -    p is an integer equal to the oxidation state of the metal M        minus r+1; it ranges from 1 to 4; and    -   (B) an alumoxane or a compound able to form an alkylmetallocene        cation.

In the metallocene compound of formula (I), the divalent bridge (ZR¹_(m))_(n) is preferably selected from the group consisting of CR¹ ₂,(CR¹ ₂)₂, (CR¹ ₂)₃, SiR¹ ₂, GeR¹ ₂, NR¹, and PR¹, R¹ having the meaningreported above; more preferably, said divalent bridge is Si(CH₃)₂,SiPh₂, CH₂, (CH₂)₂, (CH₂)₃ or C(CH₃)₂.

The ligand Cp, which is π-bonded to said metal M, is preferably selectedfrom the group consisting of cyclopentadienyl, mono-, di-, tri- andtetra-methyl cyclopentadienyl; 4-^(t)butyl-cyclopentadienyl;4-adamantyl-cyclopentadienyl; indenyl; mono-, di-, tri- and tetra-methylindenyl; 2-methyl indenyl, 3-^(t)butyl-indenyl, 4-phenyl indenyl, 4,5benzo indenyl; 3-trimethylsilyl-indenyl; 4,5,6,7-tetrahydroindenyl;fluorenyl; 5,10-dihydroindeno[1,2-b]indol-10-yl; N-methyl- orN-phenyl-5,10-dihydroindeno [1,2-b]indol-10-yl;5,6-dihydroindeno[2,1-b]indol-6-yl; N-methyl-orN-phenyl-5,6-dihydroindeno[2,1-b]indol-6-yl; azapentalene4-yl;thiapentalene-4-yl; azapentalene-6-yl; thiapentalene-6-yl; mono-, di-and tri-methyl-azapentalene-4-yl,2,5-dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene.

The group A is O, S, N(²), preferably R² is methyl, ethyl, n-propyl,isopropyl, n-butyl, t-butyl, phenyl, p-n-butyl-phenyl, benzyl,cyclohexyl and cyclododecyl; more preferably R² is t-butyl; preferably Ais N(R²) or has the same meaning of Cp.

The metal M is preferably Ti, Zr or Hf. and more preferably Zr.

The substituents X are preferably the same and more preferably, thesubstituents X are selected from the group consisting of —Cl, —Br, -Me,-Et, -n-Bu, -sec-Bu, -Ph, -Bz, —CH₂SiMe₃, —OEt, —OPr, —OBu, —OBz and—NMe₂.

The variable m is preferably 1 or 2.

The variable n ranges preferably from 1 to 2, when n>1, the atoms Z canbe the same or different from each other, such as in divalent bridgesCH₂—O, CH₂—S and CH₂—Si(CH₃)₂.

The variable p is preferably 2.

Non limiting examples of compounds belonging to formula (1) are the racand meso form (when present) of the following compounds:

-   bis(cyclopentadienyl)zirconiumdichloride;-   bis(indenyl)zirconiumdichloride;-   bis(tetrahydroindenyl)zirconiumdichloride;-   bis(fluorenyl)zirconiumdichloride;-   (cyclopentadienyl)(indenyl)zirconiumdichloride;-   (cyclopentadienyl)(fluorenyl)zirconiumdichloride;-   (cyclopentadienyl)(tetrahydroindenyl)zirconiumdichloride;-   (fluorenyl)(indenyl)zirconiumdichloride;-   dimethylsilanediylbis(indenyl)zirconiumdichloride,-   dimethylsilanediylbis(2-methyl-4-phenylindenyl)zirconiumdichloride,-   dimethylsilanediylbis(4-naphthylindenyl)zirconiumdichloride,-   dimethylsilanediylbis(2-methylindenyl)zirconiumdichloride,-   dimethylsilanediylbis(2-methyl-4-t-butylindenyl)zirconiumdichloride,-   dimethylsilanediylbis(2-methyl-4-isopropylindenyl)zirconiumdichloride,-   dimethylsilanediylbis(2,4-dimethylindenyl)zirconiumdichloride,-   dimethylsilanediylbis(2-methyl-4,5-benzoindenyl)zirconiumdichloride,-   dimethylsilanediylbis(2,4,7-trimethylindenyl)zirconiumdichloride,-   dimethylsilanediylbis(2,4,6-trimethylindenyl)zirconiumdichloride,-   dimethylsilanediylbis(2,5,6-trimethylindenyl)zirconiumdichloride,-   methyl(phenyl)silanediylbis(2-methyl-4,6-diisopropylindenyl)-zirconiumdichloride,-   methyl(phenyl)silanediylbis(2-methyl4-isopropylindenyl)-zirconiumdichloride,-   1,2-ethylenebis(indenyl)zirconiumdichloride,-   1,2-ethylenebis(4,7-dimethylindenyl)zirconiumdichloride,-   1,2-ethylenebis(2-methyl-4-phenylindenyl)zirconiumdichloride,-   1,4-butanediylbis(2-methyl-4-phenylndenyl)zirconiumdichloride,-   1,2-ethylenebis(2-methyl4,6-diisopropylindenyl)zirconiumdichloride,-   1,4-butanediylbis(2-methylisopropylindenyl)zirconiumdichloride,-   1,4-butanediylbis(2-methyl-4,5-benzoindenyl)zirconiumdichloride,-   1,2-ethylenebis (2-methyl4,5-benzoindenyl)zirconiumdichloride,-   [4-(η⁵-cyclopentadienyl)-4,6,6-trimethyl(η⁵-4,5-tetrahydro-pentalene)]dimethylzirconium,-   [4-(η⁵-3′-trimethylsilylcyclopentadienyl)-4,6,6-trimethyl(η⁵-4,5-tetrahydropentalene)]dimnethylzirconium,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethane-dimethyltitanium,-   (methylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilyl-dimethyltitanium,-   (methylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyl-dirnethyltitanium,-   (tertbutylamido)-(2,4-dimethyl-2,4-pentadien-1-yl)dimethylsilyl-dimethyltitanium,-   bis( 1,3-dimethylcyclopentadienyl)zirconiumdichloride,-   methylene(3-methyl-cyclopentadienyl)-7-(2,5-dimethylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)zirconiumdichloride;-   methylene(3-isopropyl-cyclopentadienyl)-7-(2,5-dimethylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)zirconiumdichloride;-   methylene(2,4dimethyl-cyclopentadienyl)-7-(2,5-dimethylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)zirconiumdichloride;-   methylene(2,3,5-trimethyl-cyclopentadienyl)-7-(2,5-diinethylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)zirconiumdichloride;-   methylene-1-(indenyl)-7-(2,5-dimethylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)zirconiumdichloride;-   methylene-1-(indenyl)-7-(2,5-ditrimethylsilylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)zirconiumdichloride;-   methylene-1-(3-isopropyl-indenyl)-7-(2,5-dimethylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)zirconiumdichloride;-   methylene-1-2-methyl-indenyl)-7-(2,5-dimethylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)zirconiumdichloride;-   methylene-1-(tetrahydroindenyl)7-(2,5-dimethylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)zirconiumdichloride;-   methylene(2,4-dimethyl-cyclopentadienyl)-7-(2,5-dimethylcyclopentadienyl-[1,2-b:4,3-b′]dioxazol)zirconiumdichloride;-   methylene(2,3,5-trimethyl-cyclopentadienyl)-7-(2,5-dimethylcyclopentadienyl-[1,2-b:4,3-b′]dioxazol)zirconiumdichloride;-   methylene-1-(indenyl)-7-(2,5-dimethylcyclopentadienyl-[1,2-b:4,3-b′]dioxazol)zirconiumdichloride;-   isopropylidene(3-methyl-cyclopentadienyl)-7-(2,5-bmethylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)zirconiumdichloride;-   isopropylidene(2,4-dimethyl-cyclopentadienyl)-7-(2,5-dib-ethylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)zirconiumdichloride;-   isopropylidene(2,4-diethyl-cyclopentadienyl)-7-(2,5-dimethylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)zirconiumdichloride;-   isopropylidene(2,3,5-timethyl-cyclopentadienyl)-7-(2,5    ethylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)zirconiumdichloride;-   isopropylidene-1-(indenyl)-7-(2,5-dimethylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)zirconiumdichloride;-   isopropylidene-1-(2-methyl-indenyl)-7-(2,5-ethylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)zirconiumdichloride;-   dimethylsilandiyl-1-(2-methyl-indenyl)-7-(2,5methylcyclopentadienyl-[1,2-b:4,3-b′]dithiophene)hafiniumdichloride;-   dimethylsilanediyl(3-tert-butyl-cyclopentadienyl)(9-fluorenyl)zirconiumdichloride,-   dimethylsilanediyl(3-isopropyl-cyclopentadienyl)(9-fluorenyl)zirconiumdichloride,-   dimethylsilanediyl(3-methyl-cyclopentadienyl)(9-fluorenyl)zirconiumdichloride,-   dimethylsilanediyl(3-ethyl-cyclopentadienyl)(9-fluorenyl)zirconiumdichloride,-   1-2-ethane(3-tert-butyl-cyclopentadienyl)(9-fluorenyl)zirconiumdichloride,-   1-2-ethane    (3-isopropyl-cyclopentadienyl)(9-fluorenyl)zirconiumdichloride,-   1-2-ethane    (3-methyl-cyclopentadienyl)(9-fluorenyl)zirconiumdichloride,-   1-2-ethane    (3-ethyl-cyclopentadienyl)(9-fluorenyl)zirconiumdichloride,-   dimethylsilandiylbis-6-(3-methylcyclopentadienyl-[1,2-b]-thiophene)dichloride;-   dimethylsilandiylbis-6-(4-methylcyclopentadienyl-[1,2-b]-thiophene)zirconiumdichloride;-   dimethylsilandiylbis-6-(4-isopropylcyclopentadienyl-[1,2-b]-thiophene)zirconiumdichloride;-   dimethylsilandiylbis-6-(4-ter-butylcyclopentadienyl-[1,2-b]-tiophene)zirconiumdichloride;-   dimethylsilandiylbis-6-(3-isopropylcyclopentadienyl-[1,2-b]-hiophene)zirconiumdichloride;-   dimethylsilandiylbis-6-(3-phenylcyclopentadienyl-[1,2-b]-thiophene)zirconiumdichloride;-   dimethylsilandiylbis-6-(2,5-dimnethyl-3-phenylcyclopentadienyl-[1,2-b]-thiophene)zirconium    di methyl;-   dimethylsilandiylbis-6-[2,5-dimethyl-3-(2-methylphenyl)cyclopentadienyl-[1,2-b]-thiophene]zirconiumdichloride;-   dimethylsilandiylbis-6-[2,5-dimethyl-3-(2,4,6-trimethylphenyl)cyclopentadienyl-[1,2-b]-thiophene]zirconiumdichloride;-   dimethylsilandiylbis-6-[2,5-dimethyl-3-mesitylenecyclopentadienyl-[1,2-b]-thiophene]zirconiumdichloride;-   dimethylsilandiylbis-6-(2,4,5-trimethyl-3-phenylcyclopentadienyl-[1,2-b]-thiophene)zirconiumdichloride;-   dimethylsilandiylbis-6-(2,5-diethyl-3-phenylcyclopentadienyl-[1,2-b]-thiophene)zirconiumdichloride;-   dimethylsilandiylbis-6-(2,5-diisopropyl-3-phenylcyclopentadienyl-[1,2-b]-thiophene)zirconiumdichloride;-   dimethylsilandiylbis-6-(2,5-diter-butyl-3-phenylcyclopentadienyl-[1,2-b]-thiophene)zirconiumdichloride;-   dimethylsilandiylbis-6-(2,5-ditriethylsilyl-3-phenylcyclopentadienyl-[1,2-b]-thiophene)zirconiumdichloride;-   dimethylsilandiylbis-6-(3-methylcyclopentadienyl-[1,2-b]-silole)zirconiumdichloride;-   dimethylsilandiylbis-6-(3-isopropylcyclopentadienyl-[1,2-b]-silole)zirconiumdichloride;-   dimethylsilandiylbis-6-(3-phenylcyclop    entadienyl-[1,2-b]-silole)zirconiumdichloride;-   dimethylsilandiylbis-6-(2,5-dimethyl-3-phenylcyclopentadienyl-[1,2-b]-silole)zirconiumdichloride;-   dimethylsilandiylbis-6-[2,5    dimethyl-3-(2-methylphenyl)cyclopentadienyl-[1,2-b]-silole]zirconiumdichloride;-   dimethylsilandiylbis-6-[2,5-dimethyl-3-(2,4,6-trimethylphenyl)cyclopentadienyl-[1,2-b]-silole]zirconiumdichloride;-   dimethylsilandiylbis-6-[2,5-imethyl-3-mesitylenecyclopentadienyl-[1,2-b]-silole]zirconiumdichloride;-   dimethylsilandiylbis-6-(2,4,5-trimnethyl-3-phenylcyclopentadienyl-[1,2-b]-silole)zirconiumdichloride;-   [dimethylsilyl(tert-butylamnido)][(N-methyl-1,2-dihydrocyclopenta[2,1-b]indol-2-yl)]titaniumdichloride;-   [dimethylsilyl(tert-butyldo)][(6-methyl-N-methyl-1,2-dihydrocyclopenta[2,1-b]indol-2-yl)]titaniumdichloride;-   [dimnethylsilyl(tert-butylamido)][(6-methoxy-N-methyl-1,2-dihydrocyclopenta[2,1-b]indol-2-yl)]titaniumdichloride;-   [dimethylsilyl(tert-butylamido)][(N-ethyl-1,2-dihydrocyclopenta[2,1-b]indol-2-yl)]titaniumdichloride;-   [dimethylsilyl(tert-butylamido)][(N-phenyl-1,2-dihydrocyclopenta[2,1-b]indol2-yl)]titaniumdichloride;-   [dimethylsilyl(tert-butylamido)][(6-methyl-N-phenyl-1,2-dihydrocyclopenta[2,1-b]indol2-yl)]titaniumdichloride;-   [dimethylsilyl(tert-butylamido)][(6-methoxy-N-phenyl-1,2-dihydrocyclopenta[2,1-b]indol2-yl)]titaniumdichloride;-   [dimethylsilyl(tert-butylamido)][(N-methyl-3,4-dimethyl-1,2-dihydrocyclopenta[2,1-b]indol-2-yl)]titaniumdichloride;-   [dimethylsilyl(tert-butylarnido)][(N-ethyl-3,4-dimethyl-1,2-diydrocyclopenta[2,1-b]indol-2-yl)]titaniumdichloride;-   [dimethylsilyl(tert-butylamido)][(N-phenyl-3,4-dimnethyl-1,2-dihydroclopenta[2,1-b]indol-2-yl)]titaniumdichloride;    as well as the corresponding dimethyl, hydrochloro and dihydro    compounds.

When A is N(R²), a suitable class of metallocene complexes (A) for usein the catalysts complexes of the invention comprises the well-knownconstrained geometry catalysts, as described in EP-A-0 416 815, EP-A-0420 436, EP-A-0 671 404, EP-A-0 643 066 and WO-A-91/04257.

When the group A has the same meaning of Cp, it is preferablysubstituted or unsubstituted cyclopentadienyl, indenyl,tetrahydroindenyl (2,5-dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene).such as the metallocene complexes described in WO 98/22486, WO 99/58539WO 99/24446, U.S. Pat. No. 5,556,928, WO 96/22995, EP485822, EP-485820,U.S. Pat. No. 5,324,800 and EP-A-0 129 368.

A particularly preferred class of metallocene compounds has thefollowing formulas (IIa) or (IIb)

Wherein M, X, Z, R¹, m, n and p has been described above;

-   -   R⁴, R⁵, R⁶, R⁷, R⁸ and R⁹, equal to or different from each        other, are selected from the group consisting of hydrogen,        linear or branched saturated or unsaturated C₁-C₂₀-alkyl,        C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl,        C₇-C₂₀-arylalkyl radical, optionally containing heteroatoms        belonging to groups 13-17 of the Periodic Table of the Elements;        or two adjacent groups can form a C₄-C₇ ring optionally        containing O, S, N, P or Si atoms that can bear substituents;    -   preferably:    -   R⁴ is hydrogen, methyl, phenyl isopropyl;    -   R⁵ is hydrogen, tertbutyl, isopropyl;    -   R⁶ is hydrogen, methyl, phenyl, or form with R⁷ a condensed        benzene ring;    -   R⁷ is hydrogen or forms with R⁶ a condensed benzene ring;

When A is different from Cp another preferred class of metallocenecompounds has formula (III)

Wherein:

-   -   Wherein M, X, Z, R′, m, n and p has been described above    -   A is O, S, NR², PR² wherein R² has the meaning reported above;    -   The groups R¹⁰ equal to or different from each other are        selected from the group consisting of hydrogen, linear or        branched saturated or unsaturated C₁-C₂₀-alkyl,        C₃-C₂₀-cycloallyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl,        C₇-C₂₀-arylalkyl radical, optionally containing heteroatoms        belonging to groups 13-17 of the Periodic Table of the Elements;        or two adjacent groups can form a C₄-C₇ ring optionally        containing O, S, N, P or Si atoms that can bear substituents;    -   Preferably:    -   M is titanium; the group (R¹ _(m)Z)_(n) is selected from the        group consisting of dimethylsilyl, diphenylsilyl, diethylsilyl,        di-n-propylsilyl, di-isopropylsilyl, di-n-butyl-silyl,        di-t-butyl-silyl, di-n-hexylsilyl, ethylmethylsilyl,        n-hexylmethylsilyl, cyclopentamethylenesilyl,        cyclotetramethylenesilyl, cyclotrimethylenesilyl, methylene,        dimethylmethylene and diethylmethylene; even more preferably, it        is dimethylsilyl, diphenylsilyl or dimethylmethylene;    -   A is NR².

Preferred subclasses of metallocene compounds belonging to formula (III)have formulas (IVa) and (IVb)

wherein M, X, Z, R¹, m, n and p has been described above; Ti istitanium; A is O, S, NR², PR² wherein R² has the meaning reported above;

-   -   the groups R¹¹, R¹², R¹³, R¹⁴ and R¹⁵ are selected from the        group consisting of hydrogen, linear or branched saturated or        unsaturated C₁-C₂₀-alkyl, C₃-C₂₀-cycloallyl, C₆-C₂₀-aryl,        C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkyl radical, optionally        containing heteroatoms belonging to groups 13-17 of the Periodic        Table of the Elements; or two adjacent groups can form a C₄-C₇        ring optionally containing O, S, N, P or Si atoms that can bear        alkyl substituents;    -   Y¹ is an atom selected from the group consisting of NR¹⁶, oxygen        (O), PR¹⁶ or sulfur (S), wherein the group R¹⁶ is selected from        the group consisting of linear or branched, saturated or        unsaturated, C₁-C₂₀ alkyl, C₆-C₂₀ aryl and C₇-C₂₀ arylalkyl        radical;

Alumoxanes used as component (B) can be obtained by reacting water withan organo-aluminium compound of formula H_(j)AlR¹⁷ _(3-j) or H_(j)Al₂R¹⁷_(6-j), where R¹⁷ substituents, same or different, are hydrogen atoms,halogen atoms, C₁-C₂₀-alkyl, C₃-C₂₀-cyclalkyl, C₆-C₂₀-aryl,C₇-C₂₀-alkylaryl or C₇-C₂₀-arylalkyl, optionally containing silicon orgermanium atoms with the proviso that at least one R¹⁷ is different fromhalogen, and j ranges from 0 to 1, being also a non-integer nurnber. Inthis reaction the molar ratio of Al/water is preferably comprisedbetween 1:1 and 100:1.

The molar ratio between aluminium and the metal of the metallocene iscomprised between about 10:1 and about 20000:1, and more preferablybetween about 100:1 and about 5000:1.

The alumoxanes used in the catalyst according to the invention areconsidered to be linear, branched or cyclic compounds containing atleast one group of the type:

wherein the substituents R¹⁷, same or different, are described above.

In particular, alumoxanes of the formula:

can be used in the case of linear compounds, wherein n¹ is 0 or aninteger from 1 to 40 and the substituents R¹⁷ are defined as above, oralumoxanes of the formula:

can be used in the case of cyclic compounds, wherein n¹ is an integerfrom 2 to 40 and the R¹⁷ substituents are defined as above.

Examples of alumoxanes suitable for use according to the presentinvention are methylalumoxane (MAO), tetra-(isobutyl)alumoxane (TIBAO),tetra-(2,4,4-trimethyl-pentyl)alumoxane (TIOAO),tetra-(2,3-dimethylbutyl)alumoxane (TDMBAO) andtetra-(2,3,3-trirnethylbutyl)alumoxane (IMBAO).

Particularly interesting cocatalysts are those described in WO 99/21899and in WO01/21674 in which the alkyl and aryl groups have specificbranched patterns.

Non-limiting examples of aluminium compounds according to said PCTapplications are: tris(2,3,3-trimethyl-butyl)aluminium,tris(2,3-dimethyl-hexyl)aluminium, tris(2,3-dimethyl-butyl)aluminium,tris(2,3-dinethyl-pentyl)aluminium, tris(2,3-dimethyl-heptyl)aluminium,tris(2-methyl-3-ethyl-pentyl)aluminium,tris(2-methyl-3-ethyl-hexyl)aluminium,tris(2-methyl-3-ethyl-heptyl)aluminium,tris(2-methyl-3-propyl-hexyl)aluminium,tris(2-ethyl-3-methyl-butyl)aluminium,tris(2-ethyl-3-methyl-pentyl)aluminium,tris(2,3-diethyl-pentyl)aluminium,tris(2-propyl-3-methyl-butyl)aluminium,tris(2-isopropyl-3-methyl-butyl)aluminium,tris(2-isobutyl-3-methyl-pentyl)aluminium,tris(2,3,3-trimethyl-pentyl)alumninium,tris(2,3,3-trimethyl-hexyl)aluminium,tris(2-ethyl-3,3-dimethyl-butyl)aluminium,tris(2-ethyl-3,3-dimethyl-pentyl)aluminium,tris(2-isopropyl-3,3-dimethyl-butyl)aluminium,tris(2-trimethylsilyl-propyl)aluminium,tris(2-methyl-3-phenyl-butyl)aluminium,tris(2-ethyl-3-phenyl-butyl)aluminium,tris(2,3-dimethyl-3-phenyl-butyl)aluminium,tris(2-phenyl-propyl)aluminium,tris[2-(4-fluoro-phenyl)-propyl]aluminium,tris[2-(4-chloro-phenyl)-propyl]aluminium,tris[2-(3-isopropyl-phenyl)-propyl]aluminium,tris(2-phenyl-butyl)aluminium, tris(3-methyl-2-phenyl-butyl)aluminium,tris(2-phenyl-pentyl)aluminium,tris[2-(pentafluorophenyl)-propyl]aluminium,tris[2,2-diphenyl-ethyl]aluminium andtris[2-phenyl-2-methyl-propyl]aluminium, as well as the correspondingcompounds wherein one of the hydrocarbyl groups is replaced with ahydrogen atom, and those wherein one or two of the hydrocarbyl groupsare replaced with an isobutyl group.

Amongst the above aluminium compounds, trimethylaluminium (TMA),triisobutylaluminium (TI3AL), tris(2,4,4-trimethyl-pentyl)aluminium(TIOA), tris(2,3-dimethylbutyl)aluminiumn (TDMBA) andtris(2,3,3-trimethylbutyl)aluminium (TTMBA) are preferred.

Non-limiting examples of compounds able to form an alkylmetailocenecation that can be used as component (B) are compounds of formula D⁺E⁻,wherein D⁺ is a Brønsted acid, able to donate a proton and to reactirreversibly with a substituent X of the metallocene of formula (I) andE⁻ is a compatible anion, which is able to stabilize the activecatalytic species originating from the reaction of the two compounds,and which is sufficiently labile to be able to be removed by an olefinicmonomer. Preferably, the anion E⁻ comprises of one or more boron atoms.More preferably, the anion E⁻ is an anion of the formula BAr₄ ⁽⁻⁾,wherein the substituents Ar which can be identical or different are arylradicals such as phenyl, pentafluorophenyl orbis(trifluoromethyl)phenyl. Tetrakis-pentafluorophenyl borate isparticularly preferred examples of these compounds are described in WO91/02012. Moreover, compounds of the formula BAr₃ can conveniently beused. Compounds of this type are described, for example, in WO 92/00333.Other examples of compounds able to form an alkylmetallocene cation arecompounds of formula BAr₃P wherein P is a substituted or unsubstitutedpyrrol radicals, and B is a boron atom. These compounds are described inWO01/62764. All these compounds containing boron atoms can be used in amolar ratio between boron and the metal of the metallocene comprisedbetween about 1:1 and about 10:1; preferably 1:1 and 2.1; morepreferably about 1:1.

Non limiting examples of compounds of formula D⁺E⁻ are:

-   Triethylammoniumtetra(phenyl)borate,-   Tributylammoniumtetra(phenyl)borate,-   Trimethylammoniumtetra(tolyl)borate,-   Tributylammoniumtetra(tolyl)borate,-   Tributylammoniumtetra(pentafluorophenyl)borate,-   Tributylammoniumtetra(pentafluorophenyl)aluminate,-   Tripropylammoniurntetra(dimethylphenyl)borate,-   Tributylammoniumtetra(trifluoromethylphenyl)borate,-   Tributylamrnoniumtetra(4-fluorophenyl)borate,-   N,N-Dimethylaniliniumtetra(phenyl)borate,-   N,N-Diethylariliniurntetra(phenyl)borate,-   N,N-Dimethylamlniumtetrakis(pentafluorophenyl)boratee,-   N,N-Dimethylaniliniumtetrais(pentafluorophenyl)aluminate,-   Di(propyl)ammoniumtetkis(pentafluorophenyl)borate,-   Di(cyclohexyl)amnmoniumtetrakis(pentafluorophenyl)borate,-   Triphenylphosphoniumtetrakisphenyl)borate,-   Triethylphosphoniumtetrakis(phenyl)borate,-   Diphenylphosphoniumtetraais(phenyl)borate,-   Tri(methylphenyl)phosphoniumtetrakis(phenyl)borate,-   Tri(dimethylphenyl)phosphoniumtetrakis(phenyl)borate,-   Triphenylcarbeniumtetrakis(pentafluorophenyl)borate,-   Triphenylcarbeniumtetradis(pentafluorophenyl)aluminate,-   Triphenylcarbeniumtetrakis(phenyl)alurninate,-   Ferroceniumtetrakis(pentafluorophenyl)borate,-   Fernoceniumtetrakis(pentafluorophenyl)aluminate.-   Triphenylcarbeniumtetrakis(pentafluorophenyl)borate,-   N,N-Dimethylaniliniumtetrakis(pentafluorophenyl)borate,

Further compounds that can be used are those of formula RM′-O-M′R, Rbeing an alkyl or aryl group, and M′ is selected from an element of theGroup 13 of the Periodic Table of the Elements (new IUPAC version).Compounds of this type are described, for example, in the Internationalpatent application WO 99/40129.

The catalyst system of the present invention can be supported on theporous alphaolefin polymer with various methods known in the art. Forexample to a suspension of the porous polymer, optionally containing thediene, in a solvent, such as propane, a solution or a suspension of thecatalyst system can be injected under stirring and then the solvent isremoved, for example by flashing. A particularly suitable process forsupporting the catalyst system is described in WO 01/44319 wherein theprocess comprises the steps of:

-   -   (a) preparing a catalyst solution comprising a soluble catalyst        component;    -   (b) introducing into a contacting vessel:        -   (i) a porous support material in particle form, and        -   (ii) a volume of the catalyst solution not greater than the            total pore volume of the porous support material introduced;    -   (c) discharging the material resulting from step (b) from the        contacting vessel and suspending it in an inert gas flow, under        such conditions that the solvent evaporates; and    -   (d) reintroducing at least part of the material resulting from        step (c) into the contacting vessel together with another volume        of the catalyst solution not greater than the total pore volume        of the reintroduced material.

To maximize the amount of catalyst component(s) deposited on the supportparticles the material resulting from step (d) can be subjected tofurther cycles of steps (c) and (d). The supported catalyst can besuitably recovered after a drying step (c).

The process of the present invention can also be used as the last stepof a multistep process according to WO 96/11218 and WO 96/2583. In thisway the porous alpha-olefin polymer is prepared in the first reactorthen, after the impregnation steps, ethylene, alpha-olefin and diene canbe polymerized.

Another object of the present invention is an heterophasic elastomericpolymer composition containing:

-   -   from 10% to 70% by weight, preferably between 15% and 50% by        weight, more preferably between 25% and 50% by weight of a        propylene homopolymer having the following characteristics:    -   flexural modulus (METHOD ASTM D-5023) lower than 1200 Mpa;        preferably lower than 1000 Mpa, more preferably lower than 900        Mpa;    -   in the Temperature Rising Elution Temperature analysis (IREF)        the fraction eluted at a temperature range from 25° C. to 97° is        higher then 20% preferably higher than 30%; more preferably        higher than 40% of the total polymer eluted; and    -   a melting enthalpy lower than 90 J/g; preferably lower than 80        J/g;more preferably lower than 70 J/g;    -   a pore volume greater than 0.45 cc/g (determined by mercury        absorption); preferably greater than 0.5 cc/g; more preferably        greater than 0.55 cc/g; and    -   from 30% to 90% by weight, preferably between 85% and 50% by        weight, more preferably between 75% and 50% by weight of an        ethylene, propylene and non conjugated diene terpolymer        containing:    -   from 20% to 90% by weight of ethylene derived units, more        preferably from 30% to 85% by weight of ethylene, even more        preferably from 35% to 80% by weight;    -   from 10% to 80% by weight of propylene derived units, more        preferably from 20% to 65% by weight; and    -   from 0.5% to 20% by weight of a non-conjugated dienes;        preferably from 1% to 15% by weight, and most preferably from 2%        to 10% by weight.

A further object of the present invention is a solid catalyst systemcomprising:

-   -   a porous alpha-olefin polymer impregnated with a non conjugated        diene;    -   a transition metal catalyst component; and    -   a suitable cocatalyst.

Preferably the porous alpha-olefin polymer is endowed with the followingcharacteristics:

-   -   flexural modulus (METHOD ASTM D-5023) lower than 1200 Mpa;        preferably lower than 1000 Mpa, more preferably lower than 900        Mpa;    -   in the Temperature Rising Elution Temperature analysis (REF) the        fraction eluted at a temperature range from 25° C. to 97° is        higher then 20% preferably higher than 30%; more preferably        higher than 40%; and    -   a melting enthalpy lower than 90 J/g; preferably lower than 80        J/g;more preferably lower than 70 J/g;    -   a pore volumegreater than 0.45 cc/g (determined by mercury        absorption); preferably greater than 0.5 cc/g; more preferably        greater than 0.55 cc/g.

With the polymer obtained by the process of the present invention,thermoplastic elastomeric products having optimum elastomeric propertiesand a good balance of elasto-mechanical properties can be obtained afterdynamic vulcanization.

Therefore a still further object of the present invention is a processfor preparing a thermoplastic elastomeric composition comprising puttingin contact the product obtained by the process described above withcrosslinking agents and, if appropriate, coadjuvants thereof, attemperatures of between 140° C. and 240° C.

Among the various crosslinking techniques known in the art, thepreferred technique is dynamic vulcanization. When working according tothis technique, the compositions of the invention are subjected tokneading or to other shear forces in the presence of crosslinking agentsand, if appropriate, coadjuvants thereof, at temperatures between 140°C. and 240° C., preferably at temperatures higher than the melting pointof the crystalline phase. The compositions of the invention can beimpregnated with an oil extender for regulating their hardness, eitherbefore the addition of the crosslinking agent or at the start or end ofvulcanization. The oil extender used can be of various types, forexample aromatic, naphthenic or preferably paraffinic. It is used inquantities such that weight ratios between the oil extender andcomponent B of between 1:5 and 5:1, preferably between 1:2 and 2:1, areobtained.

The crosslinling agents which can be used are those commonly known inthe art, such as organic peroxides, phenolic resins and sulphur. Theselection of the crosslinking agent influences the properties of thefinal product. For example, by using phenolic resins a well known TWVcan be obtained.

As coadjuvant compounds for the crosslnking, liquid 1,2-polybutadiene orcompounds of the triallyl cyanurate type can be used.

Before they are subjected to dynamic vulcanization, the compositions ofthe invention can be charged with various additives, such as heatstabilizers, antioxidants, mineral fillers or any other type of agentscustomarily used in the art.

EXAMPLES

General Procedures

The data shown in the Examples relative to the properties of the porouspolymers of the present invention were determined according to themethods indicated below.

MIL Flow Index: ASTM-D 1238

Intrinsic viscosity (I.V.): Measured in tetrahydronaphtalene (THN) at135° C.

Fraction Soluble in Xylene:

2 g of polymer were dissolved in 250 ml of xylene at 135° C. understirring. After 20 minutes the solution was left to cool, still understirring, up to 25° C. After 30 minutes the precipitated material wasfiltered through filter paper, the solution was evaporated in nitrogencurrent and the residual was dried under vacuum al 80° C until itreached constant weight. Thus, the percentage of polymer soluble inxylene at room temperature was calculated.

Porosity (mercury): determined by immersing a known quantity of thesample in a known quantity of mercury inside a dilatometer and graduallyhydraulically increasing the pressure of the mercury. The pressure ofintroduction of the mercury in the pores is in function of the diameterof the same.

The measurement was carried out using a porosimeter “Torosimeter 2000Series” (C. Erba).

The total porosity was calculated from the volume decrease of themercury and the values of the pressure applied.

The porosity expressed as percentage of voids is determined byabsorption of mercury under pressure. The volume of mercury absorbedcorresponds to the volume of the pores. For this determination, acalibrated dilatometer (diameter 3 mm) CD3 (Carlo Erba) connected to areservoir of mercury and to a high-vacuum pump (1.10⁻² mbar) is used. Aweighed amount of sample (about 0.5 g) is placed in the dilatometer. Theapparatus is then placed under high vacuum (<0.1 mm Hg) and ismaintained in these conditions for 10 minutes. The dilatometer is thenconnected to the mercury reservoir and the mercury is allowed to flowslowly into it until it reaches the level marked on the dilatometer at aheight of 10 cm. The valve that connects the dilatometer to the vacuumpump is closed and the apparatus is pressurised with nitrogen (2,5Kg/cm²). Under the effect of the pressure, the mercury penetrates intothe pores and the level goes down according to the porosity of thematerial. Once the level at which the mercury has stabilised has beenmeasured on the dilatometer, the volume of the pores is calculated fromthe equation V=R2πΔH, where R is the radius of the dilatometer and ΔH isthe difference in cm between the initial and the final levels of themercury in the dilatometer. By weighting the dilatometer,dilatometer+mercury, dilatometer+mercury+sample, the value of theapparent volume V₁ of the sample prior to penetration of the pores canbe calculated. The volume of the sample is given by:V ₁ =[P ₁−(P ₂ −P)]/D

P is the weight of the sample in grams, P₁ is the weight of thedilameter+mercury in grams, P₂ is the weight of thedilatometer+mercury+sample in grams, D is the density of mercury (at 25°C.=13,546 g/cm). The percentage porosity is given by the relation: X =(100V)/V₁. Bulk density: DIN-53194. Morphology: ASTM-D-1921-63. Flexuralmodulus: ASTM D-5023. Compression. Set: ASTM D395 22 hr/70° C. HardnessShore A: ASTM D2240. Modulus 100, psi: ASTM D412. Tensile strength: ASTMD412. Elongation: ASTM D412. Tension set: ASTM D412.

Temperature Rising Elution Fractionation (TREF) Tecnique: carried out asdescribed in EP 658 577.

Preparation of the Polypropylene Matrix A

The solid titanium catalyst component was prepared according to example2 of EP-A-395 083. Using 0.011 g of this solid, a propylenepolymerization was carried out in a 4 1 autoclave equipped withmagnetically driven stirrer and a thermostatic system, previously fluxedwith nitrogen at 70° C. for one hour and then with propylene. Into thereactor at room temperature, without stirring but under propylenestream, a catalyst system consisting of a suspension of the solidcomponent in 15 ml of hexane, 1.14 g of triethylaluminiumn, and 114 mgof dicyclopentyldimethoxysilane (donor D) is introduced, this system isprepared just prior to its use in the polymerization test.

The autoclave is then closed and 3 1 of hydrogen are introduced. Understirring, 1.3 Kg of propylene was charged and the temperature wasbrought to 70° C. in 5 minutes, maintaining the value constant for twohours. At the end of the test, the stirring was stopped and theunreacted propylene was vented off. After cooling the autoclave to roomtemperature, the polymer is recovered and then dried at 70° C. under anitrogen stream in an oven for 3 hours. 418 g of spherical polymer. Thecharacteristics of the polymer are reported in table 1.

Preparation of the Polypropylene Matrix B

The solid titanium catalyst component was prepared according to example2 of EP-A-395 083. A polymerization reactor was heated to 70° C., purgedwith a slow argon flow for 1 hour, its pressure was then raised to 100psi-g with argon at 70° C. and then the reactor was vented. Thisprocedure was repeated 4 more times. The reactor was then cooled to 30°C. Separately, into an argon purged addition funnel, the following wereintroduced in the order thay are listed; 75 mL of hexane, 4.47 mL of 1.5M solution of triethylaluminum (TEAL) (0.764 g 6.70 mmol) in hexane,approximately 0.340 mmol of dicyclopentyl dimetoxy silane (donor D)(TEAL/D about 20:1) and allowed to stand for 5 minutes. Of this mixture,35 mL was added to a flask. Then 0.0129 of the catalyst componentpreviously prepared was added to the flask and mixed by swirling for aperiod of 5 minutes. The catalytic complex so obtained was introduced,under an argon purge, into the polymerization reactor at roomtemperature. The remaining hexane/TEAILsilane solution was then drainedfrom the additional fimnel to the flask, the flask was swirled anddrained into the reactor and the injection valve was closed. Thepolymerization reactor was slowly charged with 2.2. L of liquidpropylene and H₂ while string. Then the reactor was heated to 70° C.maintaining the temperature and pressure constant for about 2 hours.After about two hours agitation was stopped and the remaining propylenewas slowly vented. The reactor wwas heated to 80° C., pured with argonfor 10 minutes and then cooled to room temperature and opened. Thepolymer waas removed and dried in a vacuum oven at 80° C. for 1 hour.

The characteristics of the polymer are reported in table 1.

Preparation of the Polypropylene Matrix C

The procedure for the preparation of the polymer matrix B was followedexcepting that butylmethyldimetoxy silane (BuMeMS) was used as externaldonor instead of dicyclopentyl dimetoxy silane.

The characteristics of the polymer are reported in table 1.

Preparation of the Polypropylene Matrix D

The procedure for the preparation of the polymer matrix B was followedexcepting that Octilmethyldimetoxy silane (OctMeMS) was used as externaldonor instead of dicyclopentyl dimetoxy silane.

The characteristics of the polymer are reported in table 1.

Example 1-4

The type and amount of the polypropylene matrix indicated in table 2 wascharged into a reactor of 4 L of capacity, under propane atmosphere(pressure 1 bar), at room temperature, without any stirring, then 250 gof propane were added at room temperature under stirring (a pressure ofabout 10 bar was achieved). 4,4 g of 5-ethylidene-2-norbomene (ENB) wereadded thereafter, by a little nitrogen overpressure, under stirring atroom temperature for 10 minutes and then propane was flashed understirring.

Further 250 g of propane were then added at room temperature understirring and the temperature was brought to 40° C. In the meantime, acatalyst solution was prepared by dissolvingrac-ethylenbis(tetrahydroindenyl)ZrCl₂ (rac EBTHIZrCl₂), methylalumoxane (MAO) and Al(isooctyl)₃ (TIOA) in 10 ml of toluene at roomtemperature (amounts reported in table 2). After 10 minutes the catalystsolution was injected into the reactor by a little nitrogenoverpressure. The suspension in the reactor was stirred at 40° C. for 10minutes. Then the reactor was vented. Propane was added thereto, toachieve a pressure of 6 bar-g at 30° C. A 50/50 ethylene/propylenemixture was fed to the reactor, in 5 minutes, bringing the pressure to20 bar-g and the temperature to 60° C. During the whole course of thepolymerisation the temperature was kept constant at 60° and the pressuretoo was maintained constant at 20 bar-g by continuously feeding anethylene/propylene mixture in a 60/40 wt/wt ratio. During thepolymerisation 16 ml of a pentane solution containing an amount of ENBreported in table 1 was continuously added dropwise.

The polymerisation was stopped by quickly degassing the monomers. Thepolymer was plunged in 800 ml of methanol and filtered.

The filtered polymer was plunged again in 800 ml of methanol containingIrganox 1020, added to be about 200 ppm on the polymer.

Methanol was then evaporated with a nitrogen stream under reducedpressure at 60° C.

Polymerization data and characterization data of the obtained polymersare reported in table 2.

Vulcanization

The polymer obtained in examples 1-4 were vulcanized in a Brabendermixer by mixing the polymers until the plastic phase melt and the torqueleveled off. At that time the cure system was added and mixing wascontinued for 4 minutes. The material was mixed at 80° C. and 100 RPMand the temperature rised during cure to about 200° C. The compositionof the cured polymer is reported in table 3. Properties of thevulcanized polymers are reported in table 4. TABLE 1 Bulk flexuralmelting melt- Pore Average TREF PP H₂ I.V. XSRT density modulus enthalpying volume radius 25-97° C. Matrix Mol % (dl/g) % g/cc Mpa J/g pointcc/g μm % A n.a. 1.49 3.50 0.36 n.a. n.a. n.a 0.54 8.7 n.a. B 0.15 2.123.35 0.29 1500  89 164.8 0.67 15  8.0 C 0.10 1.53 9.24 0.31 920 87 159.90.58 14 41.0 D 0.10 1.48 n.a. 0.30 830 106  159.8 0.66 15 40.3n.a. = not available

TABLE 2 PP Split I.V. Matrix EBTHI MAO TIAO Al/ Diene Time Activity ENBEt % rubber tot Ex (g) mg mmol mmol Zr g min Kg/gcat % wt wt % wt (dl/g)1 A (175) 14 1.09 5.47 200 7.9 120 23.7 2.0 65 62 2.8 2 B (150) 14 1.095.47 200 9.7 55 22.5 2.5 61 68 2.0 3 C (150) 8 0.63 3.13 200 6.6 16030.6 2.0 64 62 2.1 4 D (150) 8 0.63 3.13 200 8.36 110 37.5 2.3 61 68 2.0

TABLE 3 EX 1 2 3 4 polymer 161 149 161 149 Paraffinic Oil Flexon 876 8080 80 80 Talc 20 20 20 20 ZnO 5 5 5 5 Resin SP 1055 4 4 4 4Units are expressed as part by weight

Units are expressed as part by weight TABLE 4 E N B Tension SetCompression. C2 in in 100% room Set 50% 100% 200% Ultimate Tensile PPEPDM EPDM temperature 22 hr/70° C. Hardness Modulus Modulus ModulusElongation Strength Ex wt % wt % wt % % % Shore A MPa MPa MPa % MPa 1 3865 2.0 20 61 82 2.9 3.6 4.5 490 6.7 2 32 61 2.5 19 75 76 2.7 3.4 4.4 3104.9 3 33 61 2.3 12 49 73 2.3 3.0 4.1 440 6.9 4 38 64 2.0 14 53 81 3.13.8 5.1 445 9.7

1. A process for the preparation of elastomeric polymer compositionscomprising polymerizing ethylene, an alpha-olefin CH₂═CHL, where L is analkyl, cycloalkyl or aryl radical with 1-10 carbon atoms and anon-conjugated diene in the presence of a catalyst system comprising atransition metal catalyst component supported on a porous alpha-olefinpolymer, wherein at least part of the diene is impregnated on the porousalpha-olefin polymer.
 2. The process according to claim 1 wherein theporous alpha-olefin polymer has a pore volume greater than 0.45 cc/g(determined by mercury absorption).
 3. The process according to claim 1comprising the following steps: a) impregnating the porous alpha-olefinpolymer with, in any order, the non conjugated diene and the catalystsystem based on a transition metal compound, thereby forming a supportedcatalyst and b) polymerizing ethylene, the alpha olefin of formulaCH2=CHL where L is an alkyl, cycloalkyl or aryl radical with 1-10 carbonatoms, and optionally a non conjugated diene in the presence of thesupported catalyst obtained in step a).
 4. The process according toclaim 3 wherein step a) comprises the following substeps: a1) firstimpregnating athe porous alpha-olefin polymer with the non conjugateddiene; and then a2) impregnating the porous alpha-olefin polymerobtained in step al) with the catalyst system based on a transitionmetal compound.
 5. The process according to claim 1 wherein thepolymerization process is carried out in a gas phase.
 6. The processaccording to claim 5 wherein the polymerization process is carried outin a fluidized bed reactor.
 7. The process according to claim 1 whereinthe porous alpha-olefin polymer is used in an amount between 10% and 70%by weight of the total polymer produced.
 8. The process according toclaim 1 wherein the porous alpha-olefin polymer is an homopolymer orcopolymer of propylene.
 9. The process according to claim 8 wherein theporous propylene homopolymer has the following characteristics: flexuralmodulus lower than 1200 MPa; in the Temperature Rising ElutionTemperature analysis (TREF) the fractions eluted at a temperature rangefrom 25° C. to 97°, is higher than 20% of the total polymer eluted; amelting enthalpy lower than 90 J/g; a pore volume greater than 0.45cc/g.
 10. The process according to claim 3 wherein the polymer preparedin step b) contains from 20% to 90% by weight of ethylene derived units,from 10% to 80% by weight of an alpha-olefin derived units, and from0.5% to 20% by weight of a non conjugated diene.
 11. The processaccording to claim 1 wherein the catalyst system comprises a compound ofTi, not containing Metal-π bonds (Ziegler/Natta), and a Mg halide,optionally containing at least one electron donor compounds, a compoundof V or a metallocene compound.
 12. The process according to claim 11wherein the catalyst system comprises: A) a compound of formula TiCl₄,TiCl₃ or Ti(OT¹)_(f)T² _(g-f), wherein T¹ is a hydrocarbon radicalcontaining up to 15 carbon atoms or a —COT³ group, T³ is a hydrocarbonradical containing up to 15 carbon atoms, T² is a halogen, f ranges from1 to 4 and g is the valence of titanium, supported on Mg halide; B) aninternal electron-donor; C) an aluminium-alkyl compound (Al-alkyl); andoptionally D) at least one external electron-donors.
 13. The processaccording to claim 11 wherein the catalyst system comprises: A) acompound of formula VCl₃, VCl₄, VOCl₃, vanadyl halides, VO(Ac)₃,V(Acac)₃ or VO(OT⁴)₃ where T⁴ is a C₁-C₁₀ alkyl group, Ac is an acetategroup and Acac is an acetoacetate group; and B) an aluminium-alkylcompound (Al-alkyl).
 14. The process according to claim 11 wherein thecatalyst system comprises: (A) a compound belonging to the followingformula (I)(Cp)(ZR¹ _(m))_(n)(A)_(r)MX_(p)   (I) wherein (ZR¹ _(m))_(n) is adivalent group bridging Cp and A, Z is C, Si, Ge, N or P, and the R¹groups, equal to or different from each other, are hydrogen or linear orbranched, saturated or unsaturated C₁-C₂₀ alkyl, C₃-C₂₀ cycloalkyl,C₆-C₂₀ aryl, C₇-C₂₀ alkylaryl or C₇-C₂₀ arylalkyl groups or two R¹ canform a aliphatic or aromatic C₄-C₇ ring;  Cp is a substituted orunsubstituted cyclopentadienyl group, optionally condensed to one ormore substituted or unsubstituted, saturated, unsaturated or aromaticrings, containing from 4 to 6 carbon atoms, optionally containing one ormore heteroatoms;  A is O, S, NR², or PR² wherein R² is hydrogen, alinear or branched, saturated or unsaturated C₁-C₂₀ alkyl, C₃-C₂₀cycloalkyl, C₆-C₂₀ aryl, C₇-C₂₀ alkylaryl or C₇-C₂₀ arylalkyl, or A is asubstituted or unsubstituted cyclopentadienyl group, optionallycondensed to one or more substituted or unsubstituted, saturated,unsaturated or aromatic rings, containing from 4 to 6 carbon atoms,optionally containing one or more heteroatoms;  M is a transition metalbelonging to group 4, 5 or to the lanthanide or actinide groups of thePeriodic Table of the Elements (IUPAC version);  the substituents X,equal to or different from each other, are monoanionic sigma ligandsselected from the group consisting of hydrogen, halogen, R³, OR³, OCOR³,SR³, NR³ ₂ and PR³ ₂, wherein R³ is a linear or branched, saturated orunsaturated C₁-C₂₀ alkyl, C₃-C₂₀ cycloalkyl, C₆-C₂₀ aryl, C₇-C₂₀alkylaryl or C₇-C₂₀ arylalkyl group, optionally containing one or moreSi or Ge atoms;  m is 1 when Z is N or P, and it is 2 when Z is C, Si orGe;  n is an integer ranging from 0 to 4;  r is 0, 1 or 2; n is 0 when ris 0 or 2;  p is an integer equal to the oxidation state of the metal Mminus r+1; it ranges from 1 to 4; and (B) one or more alumoxanes orcompounds that form an alkylmetallocene cation.
 15. An heterophasicelastomeric polymer composition containing: from 10% to 70% by weight,of a propylene homopolymer having the following characteristics:flexural modulus lower than 1200 MPa; in the Temperature Rising ElutionTemperature analysis (TREF) the fraction. eluted at a temperature rangefrom 25° C. to 97°, is higher than 20% of the total polymer eluted; amelting enthalpy lower than 90 J/g; a pore volume greater than 0.45cc/g; and from 30% to 90% by weight, an ethylene, propylene and nonconjugated diene terpolymer containing: from 20% to 90% by weight ofethylene derived units; from 10% to 80% by weight of propylene derivedunits; and from 0.5% to 20% by weight a non-conjugated dienes derivedunits.
 16. A solid catalyst system comprising: a porous alpha-olefinpolymer impregnated with a non conjugated diene; a transition metalcatalyst component; and a cocatalyst.
 17. A process for preparing athermoplastic elastomeric composition comprising contacting a productobtained by a process comprising polymerizing ethylene, an alpha-olefinCH₂═CHL, where L is an alkyl, cycloalkyl or aryl radical with 1-10carbon atoms and a non-conjugated diene in the presence of a catalystsystem comprising a transition metal catalyst component supported on aporous alpha-olefin polymer, wherein at least part of the diene isimpregnated on the porous alpha-olefin polymer with crosslinking agentsand, optionally coadjuvants of the crosslinking agents, at temperaturesof between 140 and 240° C.
 18. The process according to claim 12 whereinthe compound is supported on active MgCl₂.
 19. The process according toclaim 14 wherein the substituents X are the same.
 20. The processaccording to claim 14 wherein r is 0 or 1.